Invalid projection

[rclark]

Using a tif downloaded from http://www.gisat.cz/content/en/products/data-download, omnivore is unable to determine the projection of this file.

digest ~/tmp/strange-projection.tif 

/Users/r/gh/mapbox/mapnik-omnivore/lib/raster.js:78
  var current = new mapnik.Projection(this.projection);
                ^
Error: failed to initialize projection with: ''
    at Raster.getExtent (/Users/r/gh/mapbox/mapnik-omnivore/lib/raster.js:78:17)
    at Raster.getCenter (/Users/r/gh/mapbox/mapnik-omnivore/lib/raster.js:67:8)
    at /Users/r/gh/mapbox/mapnik-omnivore/index.js:80:12
    at pop (/Users/r/gh/mapbox/mapnik-omnivore/node_modules/queue-async/queue.js:24:14)
    at /Users/r/gh/mapbox/mapnik-omnivore/node_modules/queue-async/queue.js:38:39
    at /Users/r/gh/mapbox/mapnik-omnivore/index.js:75:7
    at Object.oncomplete (fs.js:108:15)

gdalinfo gives the projection information as:

LOCAL_CS["KRON        D211",
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]
Origin = (-907000.000000000000000,-933000.000000000000000)
Pixel Size = (250.000000000000000,-250.000000000000000)

cc @GretaCB @bsudekum

[knutole]

I got here from getting the same error on same file. 🎱 Did you get anywhere with this? EPSG::9001 doesn't seem to be a valid EPSG, though.

This is metadata from a text file embedded with the raster:

 Image Format           :    GeoTIFF (No Compression)
 Image Size             :    4780 Columns x 2970 Lines x 3 Bands
 Image Type             :    16-bit unsigned

 Georeference Units     : KRON        D211
 Projection             : Krovak (negative)
 Datum - Ellipsoid      : S-JTSK (Czechia) - Bessel 1841
 Grid units             : METRE

 Upper Left  Corner     :      -907000.000  E        -933000.000  N 
 Upper Right Corner     :      -429000.000  E        -933000.000  N 
 Image Centre           :      -668000.000  E       -1081500.000  N 
 Lower Left  Corner     :      -907000.000  E       -1230000.000  N 
 Lower Right Corner     :      -429000.000  E       -1230000.000  N 

 Pixel Size             :          100.000  E            100.000  N 

 Upper Left  Corner     :  11d53'57.97" E  Lon   50d50'24.00" N  Lat
 Upper Right Corner     :  18d40'22.13" E  Lon   51d22'36.52" N  Lat
 Image Centre           :  15d31'32.56" E  Lon   49d49'54.52" N  Lat
 Lower Left  Corner     :  12d34'37.17" E  Lon   48d12'22.45" N  Lat
 Lower Right Corner     :  18d59'48.63" E  Lon   48d42'54.36" N  Lat

[wilhelmberg]

Using a tif downloaded from http://www.gisat.cz/content/en/products/data-download

Don't know if it helps, but using the same tiff with Gauss-Kruger (S-42) projection works.

gdalwarp (gdalwarp -t_srs EPSG:3857 MOS_CZ_GK3_250.tif mos_wm.tif) can reproject the Gauss-Krueger one (so should mapnik-omnivore and node-gdal) and it then overlays nicely with Web Mercator tiles:

[wilhelmberg]

The Krovak (S-JTSK) seems to be EPSG:2065 http://spatialreference.org/ref/epsg/2065/

So forcing the source srs to EPSG:2065 produces an acceptable result on the Krovak tif:

gdalwarp -s_srs EPSG:2065 -t_srs EPSG:3857 MOS_CZ_KR_250.tif mos_wm.tif

[knutole]

Thanks for the clarification of this particular raster. The problem I'm having, though, is wanting to do automatic detection of projection, and for some reason gdalinfo returns EPSG:9001. Which doesn't make sense for many reasons, one being that it doesn't exist (apparently). Projections are tricky!

This raster throws corrupt for gdal.SpatialReference.validate(), so at least there's that.

[wilhelmberg]

As I see it the EPSG:9001 just refers to the unit of measure

LOCAL_CS["KRON        D211",
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]

and not to the whole projection (LOCAL_CS["KRON D211").

epsg-registry.org on EPSG:9001

I don't think there is a way to do automatic detection with files like these, that don't a have a coordinate system that can be found in the epsg registry.

[knutole]

Ok, thanks again for your clarification. I believe you're right. Thanks for your help!